A Systematic Revision of Phyllanthus Subsection Urinaria (Euphorbiaceae)

Abstract

The examination of several taxa from various tropical regions of the world, previously classified as Phyllanthus urinaria L., indicates that they do not belong to a single species. On the basis of morphology, cytology, genetics, and biometry, a new classification is presented in which the collective species P. urinaria, or “urinaria complex,” is elevated to the subsection level: Phyllanthus subsection Urinaria. Within the subsection, two subgroups may be recognized on the basis of seed coat ornamentation. Each of these lines is represented by two species which differ from each other in chromosome number: P. embergeri nov. spec. (2n = 100) and P. nozeranii nov. spec. (2n = 50) in the “spiraled” line, P. hookeri Muell. Arg. (2n = 100) and P. urinaria L. (2n = 50) in the “radiated” line. In the latter species, which has undergone diversification, two subspecies may be distinguished: P. urinaria urinaria and P. urinaria nudicarpus subspec. nova.

Pollen morphology of Philippine species of Phyllanthus (Phyllanthaceae, Euphorbiaceae s.l.)

“…Note - Rossignol et al (1987) found that species in sect. Urinaria with chromosome number 2n = 50 have 4-colporate pollen, while species with chromosome number 2n = 100 have 5-colporate pollen.…”

“…References -Punt & Rentrop 1973, Bor 1979, Long & Yu 1984, Rossignol et al 1987, Chen & Wu 1997 VII. Phyllanthus buxifolius type - Fig.…”

“…The precise usage of pollen characters in taxonomy for the small pollen size, usually around 20 -30 μm diam is difficult, therefore the aid of scanning electronic microscope (SEM) in the observation of the exine ornamentation is necessary. At least 30 pollen types were reported in 220 species of Phyllanthus studied using LM and/or SEM (Erdtman 1952, Webster 1956, 1986, Köhler 1965, Punt 1967, 1980, 1987, Punt & Rentrop 1973, Bor 1979, Meewis & Punt 1983, Long & Yu 1984, Rossignol et al 1987, Lobreau-Callen et al 1988, Chen & Wu 1997, Webster & Carpenter 2002, Wei et al 2002, Sagun & Van der Ham 2003, Santiago et al 2004). …”

Flora do Espírito Santo: Phyllanthus (Phyllanthaceae)

“…Phyllanthus urinaria é uma espécie pantropical, naturalizada em vários continentes, na região neotropical é referida para as Antilhas, Guianas, Guatemala, Honduras, Panamá, Venezuela e Brasil (Webster 1956;Rossignol et al 1987). No Brasil, ocorre em todas as regiões em floresta ombrófila densa amazônica e atlântica e em áreas de Cerrado, bordas de mata e como ruderal (Silva & Sales 2007).…”

Phyllanthus L. (Phyllanthaceae) em Pernambuco, Brasil

“…Phyllanthus recebeu atenção de diversos estudiosos (Müller 1866;Rossignol et al 1987), especialmente nas Américas (Webster 1956;1957;1958;2002ab;Webster & Burch 1967). No Brasil, estudos abordando a taxonomia de Phyllanthus são escassos.…”